1. Field of the Invention
This invention relates to the use of mobile Internet Protocol in the Universal Mobile Telephone System (UMTS) and the General Packet Radio System (GPRS), and relates in particular to the support of intra-PLMN (Public Land Mobile Network) user mobility by means of Mobile Internet Protocol.
2. Description of the Prior Art
With the rapidly growing use of Internet Protocol (IP), an effective method of supporting mobility in UMTS and GPRS by use of protocols developed by the Internet Engineering Task Force (IETF) is highly desirable.
At present, when a Mobile System (MS) moves within the PLMN, its mobility is supported by movement detection algorithms defined in RFC2002 (Request For Comments 2002). These algorithms entail the reception of mobile IP Foreign Agent (FA) advertisements (i.e. messages sent by a mobile to a set of network nodes to indicate that the mobile is attached to that network). To save radio resources, it is not advisable to send such advertisements periodically to each MS. On the other hand, there is no shared channel available to transmit the advertisements to all the MSs.